Answer by SATYAJEET RANJAN for PHP - MySQL gets value of out parameter from a stored procedure

Here is the working solution:

enter code $res = $conn->multi_query( "CALL PROCNAME(@x);SELECT @x" );if( $res ) {  $results = 0;  do {    if ($result = $conn->store_result()) {      printf( "<b>Result #%u</b>:<br/>", ++$results );      while( $row = $result->fetch_row() ) {        foreach( $row as $cell ) echo $cell, "&nbsp;";      }      $result->close();      if( $conn->more_results() ) echo "<br/>";    }  } while( $conn->next_result() );}$conn->close();